It has been known in the dental profession since at least as early as the 1920's that a toothbrush is a potential source of cross-infection if shared, and re-infection even if not shared. Germs and viruses contaminating the toothbrush from exposure to the mouth and teeth thrive in the warm and moist environment found in most bathrooms.
Toxin-producing bacterial growth along the gum line is associated with gingivitis as well as acid-induced dental caries. The Centers for Disease Control suggests that toothbrushes can harbor pathogenic organisms even after being rinsed visibly clean. Toothbrushes can contain bacteria and viruses that cause cross-infection between brushes and re-infection during illness. This is most hazardous to those individuals with periodontal disease or compromised immune systems.
Simply rinsing a toothbrush in clean water does not substantially reduce the number of pathogenic organisms as those remaining quickly grow back. Methods such as rinsing the brush in a mouthwash can reduce contamination by as much as 99%, which sounds good until one realizes that the remaining one percent can number in the tens of thousands and can multiply rapidly.
Other methods to sterilize toothbrushes have been tried. For example, autoclaving a toothbrush can result in sterilization of the brush, but damages most modern toothbrush plastics and the cost and inconvenience of autoclaving is such as to discourage the average consumer. Exposure of the brush to ultra-violet light is another method that has been effective, although again such devices are not inexpensive. Microwaving toothbrushes is effective in killing pathogens but takes 10 minutes at full power. This method produces a melted down toothbrush and therefore is ineffective. After a period of time Ultraviolet light loses its energy levels as it continues to bounce around the cylinder and becomes less effective in its ability to sanitize. Sanitation by steam in a closed contained can allow pathogens to grow in the lower part of the chamber where moisture collects, and pathogens can re-infect.
Washing a toothbrush in a dishwasher has been shown to be an effective way of sanitization, but the potential exists for cross-contamination from other brushes and from utensils if the utensil basket is used to hold the brushes. It was found too that the toothbrush could be ejected from the of the utensil basket.
What is needed is a simple, inexpensive and effective way to sanitize a toothbrush while not damaging the bristles or handle in the process. It would also be beneficial to have a way to expose more of the toothbrush, including the handle, to the sanitizing wash than is provided by a utensil basket.